Swine dysentery has plagued swine producers for many years and cost them millions of dollars annually. The disease is characterized pathologically by marked inflammation of the colon and cecal mucosa and clinically by dehydration, loss of body weight, and usually a mucohemorrhagic diarrhea. One of the major causes of swine dysentery appears to be Treponema hyodysenteriae.
Many chemotherapeutic agents and antibiotics have been evaluated for their prophylactic or therapeutic effectiveness against swine dysentery. Arsenic compounds such as arsanilic acid were among the first compounds found to be effective in the United States. However, animals treated with effective levels of arsenicals develop signs of arsenic poisoning. Sulfonamides and nitrofurans have shown limited efficacy. Antibiotics such as bacitracin, penicillin, streptomycin, chlortetracycline, oxytetracycline, and tylosin have been used with some effectiveness.
U.S. Pat. No. 4,027,034 discloses and claims a method for the prevention of swine dysentery by the oral administration of the antibiotic, monensin, to swine susceptible to the disease. Salinomycin is also said to be effective in the treatment of swine dysentery in U.S. Pat. No. 4,291,053.
The preparation of the antibiotic, avilamycin, is described in U.S. Pat. No. 3,131,126. In U.S. Pat. No. 4,185,091, avilamycin is said to be useful for promoting the growth of domestic animals when it is included in the feed for such animals. Swine are among the animals whose growth is said to be improved by the administration of avilamycin.